Packaging an arcuate planar lightwave circuit

Abstract

A package for an arcuate planar lightwave circuit (PLC) chip includes a heater plate coupled to a base by a thick and soft support layer. The arcuate PLC is attached to the heater plate by soft adhesive. A hard adhesive is applied to a multi-waveguide end of the arcuate PLC, to additionally strengthen the attachment of the arcuate PLC to the heater plate. The structure allows the mechanical stress due to fiber pull/shock/vibration to be dissipated in the support layer without introducing large wavelength shifts in the arcuate PLC. The support layer also serves as a heat insulator, facilitating uniform heating of the arcuate PLC.

What is claimed is: 
     
       1. An optical module comprising:
 a base plate; 
 a support layer located on the base plate,
 wherein the support layer has a hardness less than a first particular Shore A value; 
 
 a heater plate located on the support layer; and 
 a chip having an input at a first end and a plurality of outputs at a second end,
 wherein the chip is adhered to the heater plate, across an area spanning the first end and the second end, with a first adhesive having a hardness less than a second particular Shore A value,
 wherein the second particular Shore A value is greater than the first particular Shore A value, and 
 
 wherein the chip is adhered to the heater plate proximate the second end with a second adhesive having a hardness greater than a particular Shore D value,
 wherein the particular Shore D value is greater than the second particular Shore A value. 
 
 
 
     
     
       2. The optical module of  claim 1 , wherein
 the base plate includes a first electrical trace and a second electrical trace, 
 the first electrical trace is coupled to a first contact of the heater plate, and 
 the second electrical trace is coupled to a second contact of the heater plate. 
 
     
     
       3. The optical module of  claim 1 , wherein the chip is shaped as an arcuate slab. 
     
     
       4. The optical module of  claim 1 , wherein the chip is a planar lightwave circuit (PLC). 
     
     
       5. The optical module of  claim 1 , wherein the chip is an arrayed waveguide grating (AWG). 
     
     
       6. The optical module of  claim 5 , wherein the AWG is adhered to the base plate at a first portion and a second portion. 
     
     
       7. The optical module of  claim 6 , wherein
 a hardness of the first portion is less than the first particular Shore A value, and 
 a hardness of the second portion is less than the first particular Shore A value. 
 
     
     
       8. An optical module comprising:
 a base plate; 
 a support layer located on the base plate,
 wherein the support layer has a hardness less than a first value; 
 
 a heater plate located on the support layer; and 
 a chip having an input at a first end and a plurality of outputs at a second end,
 wherein the chip is adhered to the heater plate, across an area spanning the first end and the second end, with a first adhesive having a hardness less than a second value,
 wherein the second value is greater than the first value, and 
 
 wherein the chip is adhered to the heater plate proximate the second end with a second adhesive having a hardness greater than a third value,
 wherein the third value is greater than the second value. 
 
 
 
     
     
       9. The optical module of  claim 8 , wherein
 the base plate includes a first electrical trace and a second electrical trace, 
 the first electrical trace is coupled to a first contact of the heater plate, and 
 the second electrical trace is coupled to a second contact of the heater plate. 
 
     
     
       10. The optical module of  claim 8 , wherein the chip is shaped as an arcuate slab. 
     
     
       11. The optical module of  claim 8 , wherein the chip is a planar lightwave circuit (PLC). 
     
     
       12. The optical module of  claim 8 , wherein the chip is an arrayed waveguide grating (AWG). 
     
     
       13. The optical module of  claim 12 , wherein the AWG is adhered to the base plate at a first portion and a second portion. 
     
     
       14. The optical module of  claim 13 , wherein
 a hardness of the first portion is less than the first value, and 
 a hardness of the second portion is less than the first value. 
 
     
     
       15. A method comprising:
 affixing a base plate and a support layer together,
 wherein the support layer has a hardness less than a first value; 
 
 affixing a heater plate and the support layer together; 
 epoxying the heater plate and a chip together,
 wherein the chip has input at a first end and a plurality of outputs at a second end, and 
 wherein the chip and the heater plate are epoxied across an area, spanning the first end and the second end, with a first epoxy having a hardness less than a second value,
 wherein the second value is greater than the first value; and 
 
 
 epoxying the heater plate and the second end of the chip together with a second epoxy having a hardness greater than a third value,
 wherein the third value is greater than the second value. 
 
 
     
     
       16. The method of  claim 15 , wherein
 the base plate includes a first electrical trace and a second electrical trace, and 
 the method further includes:
 coupling the first electrical trace to a first contact of the heater plate, and 
 coupling the second electrical trace to a second contact of the heater plate. 
 
 
     
     
       17. The method of  claim 15 , wherein the chip is shaped as an arcuate slab. 
     
     
       18. The method of  claim 15 , wherein the chip is a planar lightwave circuit (PLC). 
     
     
       19. The method of  claim 15 , wherein the chip is an arrayed waveguide grating (AWG). 
     
     
       20. The method of  claim 19 , wherein
 the AWG is adhered to the base plate at a first portion and a second portion, 
 a hardness of the first portion is less than the first value, and 
 a hardness of the second portion is less than the first value.